Evaluation of relationship between the associated traits with callus induction of mature embryo and agronomic traits in different barley genotypes (Hordeum vulgare L.)

Callus production via mature embryo culture provides the possibility to regenerate plant genotypes effectively under tissue culture conditions.Screening based on an agronomic trait is a procedure to predict the outcome of tissue culture which is very expensive and time consuming.The present research was carried out to investigate the response of 42 Iranian and European barley (Hordeum vulgare L.) cultivars to mature embryo cultureand to evaluate relationship between embryo culture traits with agronomic characters. The results showed that there were highly significant differences (P 0.01) among the genotypes for callus growth rate (CGR),callus primary diameter (CPD), relative water content of callus (RWC) and callus relative growth rate (CRGR) . The cultivars AFZAL and ASTARTIS had the highest amounts of callus growth rate and complete plantlet, therefore were identified as superior cultivars. Cluster analysis using Ward’s minimum variance divided the cultivars into four groups, so thatthe cultivars of fourth group had the highest amounts of callus growth rate, callus primary diameter and relative growth rate. The results ofcorrelation coefficientsof agronomic and embryo culture traits showed that callus primary diameter had significantcorrelation coeficients with callusgrowth rate, relative growth rate, flag leaf length and plant height. Path analysis revealed that days to heading, days to anthesis and flag leaf length had the highest positive direct effects on embryo culture traits, respectively. Comparison of the response of two types of explants (mature and immature embryos) to tissue culture indicated that the mature embryos with a lower response to tissue culture at the callus induction stage had a more appropriate and higher response atcallus regeneration stage.